This invention relates to pedestrian traffic control barriers of the type including a vertical post, and a cassette mounted on the upper end of the post, the cassette incorporating a flexible tape wound on a spool, the tape being extendable in a horizontal direction from the post. The tape is extended by pulling on its free end, causing the tape to unwind from a spool within the cassette against the force of a retractor spring tending to rotate the spool so as to rewind the tape. The free end of the tape is attached to the upper end of another similar post, or in some cases to a fixed bracket on a wall, so as to establish the barrier for guiding pedestrian traffic.
In some cases, it is desirable to provide a second cassette, about midway between the upper and lower ends of the post, so that a second tape can be drawn between the two posts, the two tapes being parallel to each other and one above the other. Such a double-tape pedestrian barrier offers a number of advantages, including extra security to protect restricted areas and valuable displays, discouraging people from xe2x80x9cducking underxe2x80x9d the barrier, helping to keep children in line, and providing added guidance for the visually impaired.
In the past, double-tape pedestrian traffic control devices have been assembled in a number of ways. One approach has been to employ a two-piece post so that the lower cassette can be readily inserted into the upper end of the lower section of the post, after which the two sections of the post are assembled and the second cassette mounted on the upper end of the top section of the post. This approach is unsatisfactory because of the extra expense involved in time and materials when dealing with a two-piece post, not to mention the unattractive appearance of a two piece post as compared to a one-piece post.
Another method which has been used to provide a second, lower tape involves use of a cassette provided with a generally semicircular bracket which fits on to the outer circular contour of a post and is fastened to the exterior of the post. This arrangement is unattractive because of the exposed bracket on the exterior of the post and the fact that the cassette projects from the post rather than being incorporated within it.
It is a general object of the present invention to provide a double-tape pedestrian traffic control device employing a one-piece post which incorporates the second, or lower, cassette within the post.
To accomplish this objective, it was necessary to overcome certain problems. As a preliminary matter, it should be explained that in the traditional cassette, mounted at the upper end of the post, tension is retained in the retractor spring even when the tape is fully wound on the spool. The reason is that it is desirable for the tape to be strongly and completely pulled back into the cassette, when the barrier is being rearranged, and if there is little or no tension in the retractor spring when the tape is fully wound, retraction of the tape, near the end of the retraction movement, will be sluggish.
In the conventional cassette mounted on the upper end of the post, several narrow brackets parallel to the axis of the cassette are carried by the cassette around its periphery. One of these brackets is formed with a narrow slot through which the tape passes. A pull is fastened to the free end of the tape, outwardly of the bracket, the pull being grasped by the fingers of the user in order to pull the tape from the cassette. The pull is wider than the slot in the bracket, and hence when the pull engages the bracket, further rotation of the spool by the retractor spring is terminated, even though the retractor spring remains tensioned.
It may also be mentioned that in the conventional cassette, the upper end of the cassette is usually larger than the internal diameter of the post. As a result, when the cassette is inserted into the upper end of the post, the upper end of the cassette engages the upper end of the post and limits the movement of that cassette into the post.
Thus, in order to incorporate a second cassette into the post about midway between the ends of the latter, the external diameter of the cassette along its entire length must be smaller than the internal diameter of the post. Moreover, the brackets and pull normally preassembled with the cassette must not be present, since these elements will prevent insertion of the lower cassette into the post. However, upon removal of the brackets and pull, there is nothing to prevent rotation of the tape spool by the retractor spring until the spring is completely untensioned, which as mentioned above is an undesirable circumstance.
It is, therefore, another object of the invention to provide a double-tape pedestrian traffic barrier in which a second, or lower, cassette is insertable into a post to a point between its ends, and yet in which tension is maintained in the retractor spring even though the tape is fully wound on the cassette spool.
Additional objects and features of the invention will be apparent from the following description, in which reference is made to the accompanying drawings.